On Sat, Nov 30, 2019 at 02:17:05AM +0200, Nir Soffer wrote:
I find bytes and bits-per-second unhelpful and hard to parse. Using GiB for sizes works for common disk images, and MiB/s works for common storage throughput.
Here is an example run with this change:
$ ./nbdkit --foreground \ --unix /tmp/nbd.sock \ --exportname '' \ --filter stats \ file file=/var/tmp/dst.img \ statsfile=/dev/stderr \ --run 'qemu-img convert -p -n -f raw -O raw -T none /var/tmp/fedora-30.img nbd:unix:/tmp/nbd.sock' (100.00/100%) elapsed time: 2.313 s write: 1271 ops, 1.14 GiB, 502.63 MiB/s zero: 1027 ops, 4.86 GiB, 2153.24 MiB/s extents: 1 ops, 2.00 GiB, 885.29 MiB/s --- filters/stats/stats.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/filters/stats/stats.c b/filters/stats/stats.c index 98282e2..45bedae 100644 --- a/filters/stats/stats.c +++ b/filters/stats/stats.c @@ -49,6 +49,10 @@ #include "cleanup.h" #include "tvdiff.h"
+#define MiB 1048576.0 +#define GiB 1073741824.0 +#define USEC 1000000.0 + static char *filename; static bool append; static FILE *fp; @@ -64,34 +68,34 @@ static uint64_t extents_ops, extents_bytes; static uint64_t cache_ops, cache_bytes;
static inline double -calc_bps (uint64_t bytes, int64_t usecs) +calc_mibps (uint64_t bytes, int64_t usecs) { - return 8.0 * bytes / usecs * 1000000.; + return bytes / MiB / usecs * USEC; }
The idea isn't bad, but I think we can lose data doing this. What happens if the rate is substantially less than 1 megabit? We either ought to scale this according to the size of the number being printed, or else let the user select it. For scaling, here's some code from fio: https://github.com/axboe/fio/blob/bef74db41fb5a1607fd55cb86544165fc08acac1/l... Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://people.redhat.com/~rjones/virt-df/